Sanctification: hagiasmos [hag·ee·as·mos] Strongs 38 from 37
1) consecration, purification.
2) the effect of consecration.
2a) sanctification of heart and life.
Sanctification is used of (a) separation to God (b) the course of life befitting those so separated
Sanctification is that relationship with God into which men enter by faith in Christ and to which their sole title is the death of Christ.
Sanctification is also used in New Testament of the separation of the believer from evil things and ways.
This sanctification is God’s will for the believer and His purpose in calling him by the gospel, it must be learned from God, as He teaches it by His Word, and it must be pursued by the believer, earnestly and undeviatingly… for the holy character [hagiosune] cannot be transferred or imputed, it is an individual possession, built up, little by little, as the result of obedience to the Word of God, and of following the example of Christ, in the power of the Holy Spirit.*
This is the will of God, even your sanctification, that ye should abstain from fornication: That every one of you should know how to possess his vessel in sanctification and honour. 1 Thessalonians 4:3-4
* Vine’s complete expository dictionary of Old and New Testament words – Vine, W. E., Unger, M. F., & White, W. (1996).*